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Can A GPX Or Sd 2300 Discriminate Iron?


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I doubt that we have much gold here in Alabama, we're too far from the beach, and not much civil war fought here, so, that leaves coin shooting . However, we do have lots of iron in the ground (bad soil) and rusty nails. Will the GPX's, SD2200's or 2300's actually discriminate  iron good enough to be able to go a little deeper than my CTX3030? My CTX is good for about 4" in worst soil and 7" at best. I need something to get a little deeper. The only PI's that I've owned is the original TDI several years back and presently have a TDI SL. The original TDI was deeper than the SL and I was thinking that I could tell small iron nails while adjusting GB would lose nails at "5" on GB then continuing to hear hi conductors on down to "3" on GB. I can in no way tell a rusty nail from a high conductor with the TDL SL. Will any PI discriminate good enough to detect only high conductors? IF no, then I'm waiting on the Fisher Manta. Thanks, Joe

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Basically, no. The GPX is about as good as it gets with both tones and a shallow iron disc function, but it is far from perfect. Garrett ATX the same but not as powerful.

Minelab GPX Discrimination

GPX Iron Reject

The Manta no matter what they say will have ferrous limitations. Nature of the beast.

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Running a GP series or GPX4000 or 4500 in the Salt timing will as part of the timing lose some very small low conductors. 

Also a big DD will achieve the same. But the actual Iron Reject circuit will only reject iron target that it is sure is iron, i.e. small and deep iron will still signal as normal. 

Thanks for linking my article Steve. 

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Thanks for all the help.. Steve, I read all the 2015 treads from Paul from California...I think that is "OLD California" on some other sites. Started to message Paul but he hasn't posted in several months...just hope his health is okay....Yeah, I'm beginning to realize the PI iron limitations that you are referring to. Have only used a TDI PI machine that apparently more limited as compared to ATX, SDC, or GPX...I was just hoping that the GPX would be so deep that maybe it could discriminate iron to at least 7" in my bad soil....If it could then it would help me get beyond my VLF limit. I want to try a GPX or the newly released Fisher I Pulse AQ....Not sure when the AQ will be available for purchase and not sure if much advantage over the GPX...however, the price said to be between $2100 and $2500 is about the same as a new GPX4500....about $1000 less than a new GPX5000....if I had your money then it would be such a proble..I'd just get both. Thanks, Joe 

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The TDI rejects ferrous as well as any of them if not better due to the manual GB control. I wrote the original article about it. I can use a TDI and dig minimal ferrous, but then it gets no more or less depth than a good VLF.

Paul has left all the forums. The last place I saw him post was Findmall. He might still be on Geotech.

It would be nice to be free of monetary concerns. You own more PI detectors than I do right now.

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